Robotic seed-planting apparatus and methods

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 09/939,333, filed Aug. 24, 2001, which claims priority to U.S. Provisional Application Ser. No. 60/227,898, filed Aug. 25, 2000, and U.S. Provisional Application No. Ser. 60/261,511, filed Jan. 12, 2001.

FIELD

The present invention relates to robotic apparatus and methods for automatically removing seeds from donor locations (e.g., containers) and planting the seeds at planting locations (e.g., planting chambers).

BACKGROUND

Many types of horticultural and agricultural operations, both in a research and in a production context, involve manipulations of plant seeds and other units of plant reproductive material. For example, certain operations involve seed sorting, seed weighing, seed planting, and analogous tasks. These tasks are labor-intensive and repetitive.

The scale of modern horticultural operations, as well as other operations involving propagation of plants, is continuing to increase. With large-scale horticultural operations, it is readily appreciated that tasks such as seed manipulation, sorting, weighing, and planting ordinarily require large number of monotonous man-hours for completion. The enormous time and labor costs associated with these tasks can be prohibitive.

Hence, there is a need for automated equipment capable of performing any of various horticulturally related tasks such as seed planting.

SUMMARY

According to one representative embodiment, a robotic apparatus for planting seeds is provided. A robotic assembly of the apparatus is configured to move in three-dimensional space. A seed manipulator is carried by the robotic assembly to be positioned by the robotic assembly at selected locations in the three-dimensional space. The seed manipulator includes a probe having an end surface that is pervious to air. The probe is fluidly connectable to a vacuum source so that application of a vacuum from the vacuum source to the probe is effective to cause the end surface of the probe to pick up at least one seed whenever the end surface of the probe is positioned at a selected first location proximate to the seed. Release of the vacuum from the probe causes the end surface of the probe to release the seed at a selected second location, such as in a planting chamber. To facilitate release of the seed from the end surface of the probe, the probe may be fluidly connected to a pressurized fluid source for selectively introducing a pressurized fluid into the probe.

The apparatus also may include a cover-removal manipulator for removing and replacing a cover on a container containing seeds to be planted. The cover-removal manipulator may be carried by or mounted to the robotic assembly, along with the seed manipulator, to be the positioned by the robotic assembly at selected locations in the three-dimensional space. Alternatively, the cover-removal manipulator and the seed manipulator may be configured for independent motion on their own respective robotic assemblies.

In addition, a seed-alignment container may be provided for use in planting seeds. The seed-alignment container is configured such that seeds, when deposited in the seed-alignment container, form a row of seeds dispersed along a surface of the container. Aligning seeds in this manner allows a seed sample comprising a selected number of seeds (e.g., as few as one seed) to be removed from a larger seed population more easily with the probe than removing a seed sample from a seed population contained in a conventional seed donor jar.

In an illustrated embodiment, the seed manipulator comprises a first probe and a second probe. The first probe desirably has an end surface configured to pick up an undefined number of seeds. The second probe, in contrast, desirably has an end surface configured to pick up a selected number of seeds. The first probe may be used for picking up a seed population at a first location (e.g., from a donor seed container) and depositing the seeds in the seed-alignment container. The second probe may be used for removing a selected number of seeds from the seed population contained the seed-alignment container and planting the seeds in a planting chamber.

An apparatus for planting seeds according to another representative embodiment comprises a first probe having an end surface configured to pick up a plurality of seeds whenever vacuum is applied to the probe and the end surface is positioned proximate the plurality of seeds. A seed-dispersing container may be provided for receiving the plurality of seeds from the first probe and dispersing the seeds along a surface thereof. A second probe may be provided for picking up and planting seeds deposited in the seed-dispersing container. The second probe has an end surface configured to pick up a seed sample comprising a selected number of seeds whenever vacuum is applied to the probe and the end surface is positioned proximate the seeds in the seed-dispersing container.

A vacuum sensor may be provided for sensing and indicating the vacuum in the second probe for use in determining whether the second probe has picked up any seeds. In a disclosed embodiment, a controller is in communication with the vacuum sensor to read the output from the vacuum sensor. If a decrease in vacuum is detected, indicating that a seed sample has been picked up on the end surface of the second probe, the controller automatically moves the second probe to a selected location for planting the seed sample.

According to yet another representative embodiment, an apparatus is provided for removing seeds contained in a donor container and planting the seeds in selected planting cells. The apparatus comprises a seed-removal means for removing seeds from the donor container. A seed-alignment means may be provided for receiving seeds from the seed-removal means and aligning the seeds in a row. A seed-planting means may be provided for removing seeds from the alignment means and planting the seeds in selected planting cells.

The seed-removal means and the seed-planting means may be configured to be movable to selected positions in three-dimensional space for picking up and releasing seeds. In addition, controlling means may be provided for controlling the movement of the seed-removal means and the seed-planting means to selected positions in three-dimensional space.

An apparatus for planting seeds according to another representative embodiment comprises a first probe and a second probe configured to move in three-dimensional space. The first and second probes are fluidly connectable to a vacuum source. The first probe has an air-pervious end surface so that application of a vacuum from the vacuum source to the first probe is effective to cause the end surface to pick up a plurality of seeds at a selected first position. Release of the vacuum from the first probe causes the end surface of the first probe to release the seeds at a selected second position. The second probe has an end surface defining a selected number of apertures. The second probe is operable to pick up a selected number of seeds at the second position, upon application of a vacuum from the vacuum source to the second probe. Release of the vacuum from the second probe causes the end surface of the second probe to release the selected number of seeds at a selected third position for planting the seeds.

In another representative embodiment, an apparatus for planting seeds comprises a probe device having an apertured end surface. The probe device is fluidly connectable to a vacuum source such that, upon application of a vacuum from the vacuum source to the probe device, seeds are picked up on the end surface of the probe device. A vacuum sensing device may be operatively connected to the probe device for sensing the vacuum in the probe device, thereby detecting whether the end surface has picked up any seeds.

A method for planting seeds, according to one embodiment, comprises depositing a plurality of seeds in a seed-alignment trough to form a row of seeds aligned along a surface in the seed-alignment trough. A seed sample, comprising a selected number of seeds, less than the plurality of seeds, is removed from the seed-alignment trough and planted at a selected location. Additional seed samples may be successively removed from the seed-alignment trough and planted at respective, separate locations. In a disclosed method, seeds are removed one at a time from the seed-alignment trough and deposited in respective planting cells.

According to yet another embodiment, a method for transferring seeds contained in a donor container to selected planting chambers comprises removing multiple seeds from the donor container. The multiple seeds are then deposited in a seed-alignment container. A planting step includes removing a selected number of seeds, which may be less than the plurality of seeds, from the seed-alignment container and planting the seeds in a respective planting chamber. The planting step may be repeated until a desired number of seeds have been planted.

In another method for planting seeds, a probe having an apertured end portion is positioned at a first position to remove at least one seed from a donor container. A vacuum is applied to the probe to cause the first probe to pick up at least one seed. The probe is then positioned at a second position to deposit the at least one seed into a planter chamber, at which point the vacuum to the probe is removed to cause the seed to be released into the planter chamber.

These and other features of the invention will be more fully appreciated when the following detailed description of the invention is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a seed-planting apparatus according to one embodiment, shown here with eight donor containers and two planting trays, each having a 6×12 array of planting chambers.

FIG. 2 is a top plan view of the apparatus of FIG. <b>1</b>.

FIGS. 3 and 4 are respective perspective views of the manipulator assembly of the apparatus of FIG. 1, comprising first and second seed manipulators having first and second probe devices, respectively, for picking up and releasing seeds, and a cover-removal manipulator.

FIG. 5 is an enlarged, top plan view of the support of the apparatus of FIGS. 1 and 2, showing respective numbering of the planting trays, planting chambers, and donor jars for purposes of operating the apparatus as detailed in FIGS. 9A-9I.

FIG. 6A is an enlarged, perspective view of the lower end portion of the first probe.

FIG. 6B is an enlarged view of the first probe shown partially in section.

FIG. 7A is an enlarged, perspective view of the lower end portion of the second probe.

FIG. 7B is an enlarged view of the second probe shown partially in section.

FIG. 8 is a valving schematic for the vacuum and compressed air sources according to one embodiment.

FIGS. 9A-9D are respective portions of a flow diagram of a seed-planting program according to one embodiment for planting seeds using the apparatus of FIGS. 1 and 2.

FIG. 9E is a flow diagram of the seed-retrieval subroutine of FIG. <b>9</b>A.

FIG. 9F is a flow diagram of the seed-planting subroutine of FIGS. 9B and 9D.

FIG. 9G is a flow diagram of the ball-transfer subroutine of FIG. <b>9</b>D.

FIG. 9H is a flow diagram of the seed-removal subroutine of FIG. <b>9</b>C.

FIG. 9I is a flow diagram of the probe-cleaning subroutine of FIGS. 9B, <b>9</b>C and <b>9</b>D.

DETAILED DESCRIPTION

The methods for picking up, planting, or otherwise handling seeds with the robotic apparatus described herein may be implemented in software stored on a computer-readable medium and executed on a general-purpose computer. For clarity, only those aspects of the software germane to the invention are described; product details well-known in the art are omitted. For the same reason, the computer hardware is not described in further detail. In addition, the software can be implemented as hardware. It should thus be understood that the invention is not limited to any specific computer language, program or computer.

Referring first to FIGS. 1 and 2, there is shown a robotic apparatus <b>10</b> according to one embodiment for planting seeds. FIGS. 1 and 2 show perspective and plan views, respectively, of the apparatus <b>10</b>. As shown, the apparatus <b>10</b> generally includes a support surface <b>12</b>, for supporting a plurality of donor, or population, containers <b>14</b> that contain seeds to be planted, and first and second planting trays, or pallets <b>16</b><i>a</i>, <b>16</b><i>b</i>, respectively. The donor containers <b>14</b> may be carried by a container support <b>20</b>, which in the illustrated embodiment comprises a horizontally supported plate having apertures sized to receive individual donor containers <b>14</b>. Each of the first and second planting trays <b>16</b><i>a</i>, <b>16</b><i>b</i>, respectively, comprises a plurality of planting chambers <b>18</b> (also referred to as planting cells or cavities), which are adapted to receive a small quantity of planting soil and one or more seeds from a donor container <b>14</b>.

Positioned on the support surface <b>12</b> between the first planting tray <b>16</b><i>a </i>and the container support <b>20</b> is a seed-alignment trough <b>110</b> (also referred to herein as a seed-dispersing container or a seed-alignment container in other embodiments). As best shown in FIG. 2, the seed-alignment trough <b>110</b> in the illustrated embodiment has a substantially V-shaped configuration with inclined side surfaces <b>112</b> that intersect at a bottom <b>118</b> surface of the trough <b>110</b>. The seed-alignment trough <b>110</b> also includes inclined end surfaces <b>114</b> and an open top portion for receiving seeds. When seeds (e.g., seeds from a donor container <b>14</b>) are deposited in the trough <b>110</b>, the seeds are directed toward the bottom of the trough by the inclined surfaces <b>112</b>, <b>114</b>, thereby forming a row of seeds discretely arrayed along the bottom <b>118</b> of the trough <b>110</b>. As will be described in greater detail below, aligning the seeds in this manner allows a seed sample comprising a selected number of seeds to be removed from a larger seed population with a seed manipulator (described below) more easily than removing a seed sample from a seed population contained in a donor container <b>14</b>.

In other embodiments, the seed-alignment trough <b>110</b> may have other shapes. For example, the seed-alignment trough <b>110</b> may have a curved, or arcuate, bottom surface.

As best shown in FIG. 2, an air knife <b>116</b> can be mounted adjacent the alignment trough <b>110</b>. The air knife <b>116</b> is fluidly connectable to a pressurized gas source (e.g., compressed air). When activated, the air knife <b>116</b> directs a stream of compressed gas into the trough <b>110</b> to remove any seed debris remaining in the trough <b>110</b> between successive seed-planting operations.

The donor containers <b>14</b> may comprise standard seed-sample jars or tubes, which typically can hold up to several hundred seeds per jar. The containers <b>14</b> may have covers or caps, such as screw-on or twist-on caps, corks or rubber stoppers, or any of various other suitable coverings that serve to shield and/or capture the seeds within the containers. In addition, other forms of containers also may be used. For example, the containers may comprise cavities or wells formed in the surface of a plate. For the purposes of illustrating the cap-removal feature of the apparatus <b>10</b>, the containers in the illustrated embodiment comprise jars adapted for receiving a twist-on cap or cover.

In the embodiment shown, the first and second planting trays <b>16</b><i>a</i>, <b>16</b><i>b</i>, respectively, comprise a 6×12 array of individual planting chambers <b>18</b> (72 planting chambers per planting tray), although planting trays comprising a larger or smaller number of planting chambers also may be used. As one example, planting trays having a 13×22 array of individual planting chambers may be used (286 planting chambers per planting tray).

As shown in FIG. 5, for purposes of illustrating the operation of the apparatus <b>10</b>, the first planting tray <b>16</b><i>a </i>may be identified by a tray-identification number K=1 and the second plating tray <b>16</b><i>b </i>is identified by a tray-identification number K=2. Each planting chamber <b>18</b> of the first planting tray <b>16</b><i>a </i>is identified by a respective chamber-identification number L=1 to L=72, progressing in a right-to-left, top-to-bottom direction. Each planting chamber <b>18</b> of the second planting tray <b>16</b><i>b </i>is identified by a respective chamber-identification number L=73 to L=144, progressing in a right-to-left, top-to-bottom direction. Each planting chamber <b>18</b> is supported at known x-y coordinates on the support surface <b>12</b>. Thus, by specifying the chamber-identification number of a chamber, and the tray-identification number of the tray, which contains the chamber, the x-y coordinates, and therefore the position of that chamber may be determined.

The apparatus <b>10</b> includes a robot assembly <b>11</b> comprising a robotic head assembly <b>28</b> operable to move in three-dimensional space. In the illustrated embodiment, for example, the robotic head assembly <b>28</b> is configured to move in Cartesian x, y, and z directions relative to the support. However, the space in which the robotic assembly moves may be defined by other coordinate systems, such as a polar coordinate system. The robotic head assembly <b>28</b> also may be adapted to remove and replace caps from donor containers and then transfer seeds from donor containers to selected planting chambers.

As shown in FIGS. 1 and 2, the robotic head assembly <b>28</b> in the illustrated configuration comprises a manipulator assembly <b>29</b> mounted to a support <b>54</b>. FIGS. 3 and 4 show enlarged views the manipulator assembly <b>29</b> with the support <b>54</b> removed for clarity. As shown, the manipulator assembly <b>29</b> in the illustrated configuration includes a cover-removal manipulator <b>30</b> for removing and replacing a cover on ajar at a selected x-y-z position, and one or more seed manipulators, such as a first seed manipulator <b>32</b> and a second seed manipulator <b>34</b>, for picking up and releasing seeds at a selected x-y-z position. The first and second seed manipulators <b>32</b> and <b>34</b> are each independently movable in the z-direction and have first and second probes <b>24</b> and <b>26</b>, respectively, that are operable for picking up and depositing seeds, as will be described more fully below.

Other forms for the robotic assembly also may be used. For example, if the apparatus is used in connection with only uncovered containers, the cover-removal manipulator <b>30</b> may be optional. Still alternatively, the cover-removal manipulator <b>30</b> and each of the first and second seed manipulators <b>32</b>, <b>34</b>, respectively, may be mounted for independent movement relative to each other on their own respective movable head assemblies.

The head assembly <b>28</b> (FIGS. 1 and 2) is movable to selected x-y positions with respect to the support surface <b>12</b>. For example, as shown in FIGS. 1 and 2, the head assembly <b>28</b> is mounted to or carried by a carriage <b>35</b>. The carriage <b>35</b> includes an assembly mount <b>38</b> on which the robotic head assembly <b>28</b> is mounted. The assembly mount <b>38</b> is mounted for translational movement along a track <b>36</b> extending in the x-axis direction parallel to the plane of the support surface <b>12</b> for positioning the assembly mount <b>38</b>, and thereby the head assembly <b>28</b>, at a selected x-axis coordinate. The track <b>36</b>, with the assembly mount <b>38</b> and head assembly <b>28</b>, are mounted for translational movement along a track <b>40</b> that extends in the y-axis direction parallel to the plane of the support surface <b>12</b> for positioning the head assembly <b>28</b> at a selected y-axis coordinate. Movements of the carriage <b>35</b> along the track <b>40</b> and of the assembly mount <b>38</b> along the track <b>36</b> to selected x-y coordinates are controlled by suitable respective drive mechanisms (not shown) operatively connected to the carriage <b>35</b> and assembly mount <b>38</b>, as is well known is the art. The drive mechanisms may comprise, for example, belt-coupled motors, linear electromagnetic motors, or the like. In a working embodiment of the apparatus <b>10</b>, the robotic assembly <b>11</b> comprises a Seiko Cartesion model XM3106b11, which includes a robotic head assembly to which the cover-removal manipulator <b>30</b> and the first and second seed manipulators <b>32</b> and <b>34</b>, respectively, are mounted.

Suitable drive mechanisms also are provided for moving the cover-removal manipulator <b>30</b> and probes <b>24</b> and <b>26</b> individually to selected z-axis positions (i.e., toward and away from the support surface <b>12</b>) during operation of the apparatus <b>10</b>. These drive mechanisms are conventional, and well known to those of skill in the art.

Control of the drive mechanisms to place the head assembly <b>28</b> at selected x-y coordinates and to place each of the cover-removed manipulator <b>30</b> and probes <b>24</b>, <b>26</b> at a selected z-axis coordinate is through a control unit <b>42</b> (FIG. 1) operatively connected to the robotic assembly at <b>50</b>. As shown, the control unit <b>42</b> desirably receives user input <b>44</b>. The construction of the control unit <b>42</b>, either as a hard-wired processor or as a software-driven processor, will be appreciated from the description of the operation of the control unit <b>42</b> described below with reference to FIGS. 9A-9I.

The cover-removal manipulator <b>30</b> is carried on the lower end of a slide rod <b>60</b> (FIG. 1) for movement therewith as the slide rod <b>60</b> is raised and lowered along a z-axis <b>56</b> (FIGS. 3 and 4) to selected z-axis positions. The slide rod <b>60</b> also is operable to rotate about the z-axis <b>56</b> for causing rotation of the cover-removal manipulator <b>30</b> about the same axis. As shown in FIG. 3, the first and second seed manipulators <b>32</b> and <b>34</b>, respectively, may be mounted to a bracket <b>46</b>. Each of the first and second seed manipulators <b>32</b>, <b>34</b>, respectively, comprises a respective slide <b>80</b>, <b>82</b> coupled to the respective probes <b>24</b>, <b>26</b>. Movement of the slides <b>80</b>, <b>82</b> causes movement of their respective probes <b>24</b>, <b>26</b> along respective z-axes <b>57</b>, <b>58</b>, respectively. As noted above, the movements of the cover-removal manipulator <b>30</b> and each of probes <b>24</b>, <b>26</b> along their respective z-axes are independently controlled by respective drive mechanisms under the control of the control unit <b>42</b>.

The slide <b>82</b> may further comprise a first slide <b>82</b><i>a </i>coupled to a second slide <b>82</b><i>b</i>, which in turn carries the second probe <b>26</b>. The first and second slides <b>82</b><i>a</i>, <b>82</b><i>b</i>, respectively, are independently movable for moving the second probe <b>26</b> to selected positions along the z-axis <b>58</b>.

Construction and translational control of the three z-direction drive mechanisms can be conventional. In the illustrated embodiment, for example, the slides <b>80</b>, <b>82</b><i>a</i>, and <b>82</b><i>b </i>are bi-directional, air-actuated slides. The slide <b>80</b> is fluidly connectable to a compressed air source (not shown) to operate the slide <b>80</b> between a retracted position in which the first probe <b>24</b> is in a raised position (shown in FIGS. 3 and 4) and an extended position in which the first probe <b>24</b> is in a lowered position. The slides <b>82</b><i>a </i>and <b>82</b><i>b </i>are also fluidly connectable to a compressed air source to operate the slides <b>82</b><i>a </i>and <b>82</b><i>b </i>between respective retracted and extended positions. In the embodiment of FIGS. 3 and 4, the second probe <b>26</b> can be placed at four positions along the z-axis: (1) a first, uppermost position with both slides <b>82</b><i>a</i>, <b>82</b><i>b </i>in their retracted positions (FIGS. <b>3</b> and <b>4</b>), (2) a second position below the first position with the first slide <b>82</b><i>a </i>retracted and the second slide <b>82</b><i>b </i>extended, (3) a third position below the second position with the first slide <b>82</b><i>a </i>extended and the second slide <b>82</b><i>b </i>retracted, and (4) a fourth position below the third positions with both slides <b>82</b><i>a</i>, <b>82</b><i>b </i>in their extended positions.

In a working embodiment, the slides <b>80</b> and <b>82</b><i>a </i>comprise, for example, model number MXS8-75-ASR air slides and the slide <b>82</b><i>b </i>comprises a model number MXS8-40-ASR air slide, which are available from SMC Pneumatics Inc.

The first probe <b>24</b> is coupled to the slide <b>80</b> for movement with the slide <b>80</b> toward and away from the support surface <b>12</b> along the z-axis <b>57</b>. The first probe <b>24</b> is in fluid communication with a vacuum source (not shown) and, optionally, a source of high-pressure gas (e.g., 90 psig) (not shown) and a source of low-pressure gas (e.g., 1-2 psig) (not shown), such as respective compressed-air sources. Control of vacuum and compressed gas to the slide <b>80</b> is provided by a suitable valving arrangement, such as one or more solenoid-actuated valves, connected to the vacuum and pressure sources and under the control of the control unit <b>42</b>.

The second probe <b>26</b> likewise is coupled to the slide <b>82</b> for movement with the slide <b>82</b> toward and away from the support surface <b>12</b> along the z-axis <b>58</b>. The second probe <b>26</b> also is in fluid communication with the vacuum source and, optionally, the sources of high- and low-pressure compressed gas (e.g., air), through a suitable valving arrangement. FIG. 8 is a diagram showing one example of a valving schematic for the vacuum and compressed air sources supplying the slides <b>80</b>, <b>82</b>, the probes <b>24</b>, <b>26</b>, and clamping jaws <b>66</b> (described below).

Referring again to FIGS. 3 and 4, the details of the cover-removal manipulator <b>30</b> will now be described. As shown, the cover-removal manipulator <b>30</b> comprises a head <b>62</b> mounted on the lower end of the slide rod <b>60</b> (FIG. <b>1</b>). A clamp <b>64</b> is mounted on the lower end of the head <b>62</b>. As mentioned, the slide rod <b>60</b> may be rotated to cause a corresponding rotation of the cover-removal manipulator <b>30</b> about the z-axis <b>56</b>. The clamp <b>64</b>, in turn, includes a pair of clamping jaws <b>66</b> designed to move toward and away from one another to clamp and release, respectively, the outer rim of a cap on a seed container of the type described above. The clamping jaws <b>66</b> may be covered on the respective inwardly facing surfaces with an elastomeric material to accommodate slight variations in cap diameters, and to provide greater frictional contact with the caps. Drive mechanisms for moving the clamping jaws <b>66</b> toward and away from one another, and for rotating the clamp <b>64</b> to a desired angular orientation about the z-axis <b>56</b> are conventional and under the control of the control unit <b>42</b>.

To remove a cover from ajar, the jaws <b>66</b> are moved into position to engage the cover, and the clamp <b>64</b> (with jaws <b>66</b>) is rotated, for example, in the counterclockwise direction. An anti-rotational tab (not shown) of the jar received in a slot in the container support <b>20</b> prevents rotation of the jar as the clamp is rotated so as to permit rotation of the cover relative to the jar. The cap of a standard seed-sample jar, such as used in the seed-planting methods described herein, has a typical outer diameter of about 1.5 to 3 cm and is completely screwed on or off the threads of a jar with about one to two full rotations of the clamp <b>64</b>.

The first probe <b>24</b> (also referred to herein as the “retrieval” probe) desirably is configured to pick up an indeterminate quantity of seeds whenever the end of the first probe <b>24</b> is near or in contact with the upper surfaces of the seeds, and a vacuum is applied to the probe. In contrast, the second probe <b>26</b> (also referred to herein as the “planter” probe) desirably is configured to pick up a selected number of seeds that corresponds to the number of seeds to be planted in a planting chamber <b>18</b>.

Generally, in one approach for planting seeds with the apparatus <b>10</b>, the first probe <b>24</b> is used for picking up an entire seed population contained in a donor jar <b>14</b> and transferring the seeds to the seed-alignment trough <b>110</b>. After the seed population has been deposited in the seed-alignment trough <b>110</b>, the second probe <b>26</b> can be used for successively removing individual seed samples, each sample comprising a selected number of seeds, from the trough <b>110</b> and planting each seed sample into a selected planting chamber <b>18</b>. As used herein, the term “to plant” means to deposit or release seeds into a selected planting chamber. In addition, the first probe <b>24</b> can be used for picking up any additional seeds that remain in the alignment trough <b>110</b> after a seed-planting operation and transferring those seeds back to the donor jar <b>14</b> from which the seeds were originally removed.

Referring to FIGS. 6A and 6B, the first probe <b>24</b> has a lower end portion <b>88</b> with an end surface <b>86</b> that is generally pervious to air. In the illustrated configuration, for example, the end surface <b>86</b> comprises a fine-mesh screen, although other forms for the end surface <b>86</b> also may be used. For example, in other embodiments, the end surface can define a plurality of apertures or openings. Still alternatively, the end surface <b>86</b> may comprise a cloth or fabric-type material that is generally pervious to air. In any case, with application of a vacuum to the first probe <b>24</b>, and whenever the first probe <b>24</b> is positioned over seeds, an indeterminate quantity of the seeds will be drawn against and captured by the first probe. As used herein, whenever a probe “picks up” a seed or other particle, the seed is immobilized on the end surface of the probe without passing through the end surface. Seeds can be released from the end surface <b>86</b> of the first probe <b>24</b> by release of the vacuum. Seed release may be facilitated by application of a low-pressure fluid (e.g., 1-2 psig compressed air) to the probe from a compressed gas source.

In addition, to facilitate removal of seeds from the alignment trough <b>110</b> with the first probe <b>24</b>, the lower end portion <b>88</b> may have a generally V-shaped cross section (as best shown in FIG. 6B) that corresponds to the shape of the alignment trough <b>110</b>. This ensures that the end surface <b>86</b> of the first probe <b>24</b> can be lowered to a position that is sufficiently close enough to the bottom of the trough <b>110</b> to enable the vacuum to draw seeds against the end surface <b>86</b>. In other embodiments, the first probe <b>24</b> may be provided with a lower end portion that is not shaped to correspond with the shape of the alignment trough <b>110</b>. For example, the first probe <b>24</b> may have a cylindrical lower end portion with a flat end surface, such as shown in copending U.S. application Ser. No. 09/939,333.

The diameter d₁of the first probe <b>24</b> desirably is between about 3-5 mm, with 4.75 mm being a specific example, although larger or smaller diameter probes are contemplated, depending on seed size and the number of seeds to be picked up. Each opening in the mesh end surface <b>86</b> desirably is smaller than the dimensions of a seed to prevent passage of seeds through the mesh surface. The mesh surface in one specific implementation typically has a mesh size of about 10-20 openings/mm².

These dimensions are suitable, for example, for seeds of <i>Arabidopsis thaliana</i>, which are about 230-260 microns in diameter, and have a per-seed mass of about 15-25 micrograms. Of course, those skilled in the art will realize that the specific dimensions for the first probe <b>24</b> provided above (as well as other dimensions provided in the present application) are given to illustrate the invention and not to limit it. These dimensions can be modified as needed in different applications or situations. For example, a relatively larger mesh size with smaller openings may be used for smaller seeds and a relatively smaller mesh size with larger openings may be used for larger seeds.

Details of one embodiment of the second probe <b>26</b> are shown in FIGS. 7A and 7B. As shown, the second probe <b>26</b> in the illustrated configuration has a generally frusto-conical-shaped lower end portion <b>90</b>, which, as the lower end portion <b>88</b> of the first probe <b>24</b>, corresponds with the shape of the seed-alignment trough <b>110</b> to facilitate removal of seeds from the alignment trough <b>110</b> with the second probe <b>26</b>. The lower end portion <b>90</b> of the second probe may comprise other shapes. For example, in other embodiments, the lower end portion of the second probe <b>26</b> may be cylindrical, rectangular or any of other various shapes.

The second probe <b>26</b> may have an end surface that defines a selected number of openings or apertures for picking up a corresponding selected number of seeds. As shown in FIG. 7B, for example, the lower end portion <b>90</b> has an end surface <b>92</b> that defines a single aperture, or opening <b>94</b> for picking up one seed on the end surface <b>92</b> of the second probe <b>26</b>. The aperture <b>94</b> is dimensioned smaller than a seed to be picked up using the second probe <b>26</b>. Thus, with application of a vacuum to the second probe <b>26</b>, and whenever the lower end portion <b>90</b> of the second probe <b>26</b> is positioned at or near a seed, the seed will be drawn against the end surface <b>92</b> at the aperture <b>94</b>. The seed can be released from the end surface <b>92</b> of the second probe <b>26</b> by release of the vacuum. Seed release may be facilitated by application of a low-pressure fluid (e.g., 1-2 psig compressed air) to the probe from a compressed gas source.

The diameter d₂of the second probe <b>26</b> desirably is between about 3-5 mm, with 4.75 mm being a specific example, although larger or smaller diameter probes also may be used. For use with seeds of <i>Arabidopsis thaliana</i>, the aperture <b>94</b> in the second probe <b>26</b> desirably is about 100 to 160 microns in diameter, although the size and shape of the aperture <b>94</b> may vary depending on the size of the seed to be picked up. By way of further example, the mesh sizes for the first probe <b>24</b> and the aperture sizes for the second probe <b>26</b> described above can be within a size range appropriate for manipulating seeds from any of various genera from the family Orchidaceae.

In the seed-planting methods described herein, the second probe <b>26</b> is used to deposit or plant a single seed in selected planting chambers <b>18</b>. Other methods, however, may involve planting a seed sample comprising more than one seed in selected planting chambers. In such cases, the number of apertures in the end surface of the second probe <b>26</b>, and thereby the number of seeds picked up by the second probe <b>26</b>, may be selected to correspond to the number of seeds to be planted in a planting chamber. For example, if two seeds are to be planted in a planting chamber, then the second probe <b>26</b> may be provided with two apertures so that at least two seeds can be picked up on the end surface of the probe.

A suitable vacuum-sensing device, such as a conventional vacuum sensor <b>96</b> (FIG. <b>8</b>), may be provided to sense the vacuum level in the second probe <b>26</b>. The vacuum sensor <b>96</b> desirably is operatively connected to the control unit <b>42</b>. In this manner, the control unit <b>42</b> can be programmed to read measurements taken by the vacuum sensor as the second probe <b>26</b> is moved along the bottom of the alignment trough <b>110</b> for picking up seeds. Whenever a decrease in vacuum in the second probe <b>26</b> is sensed by the vacuum sensor <b>96</b>, indicating that a seed has been picked up by the second probe <b>26</b>, the control unit <b>42</b> moves the second probe <b>26</b> out of and away from the alignment trough <b>110</b> to a position just above a selected planting chamber <b>18</b> for planting the seed.

The apparatus <b>10</b> may also be provided with suitable indicating elements for placing in any seed-less planting chambers (planting chambers in which a seed had not been planted during a seed-planting operation). In this manner, personnel monitoring the growth of the seeds in the planting chambers will be able to easily identify and distinguish the seed-less planting chambers from those planting chambers in which a seed had been planted but no growth occurred.

As shown in FIGS. 1, <b>2</b> and <b>5</b>, for example, indicating elements are provided in the form of a plurality of indicating balls <b>130</b>, although other forms of indicating elements also may be used. The balls <b>130</b> are contained in an elongated tube <b>132</b>, which is supported on the support surface <b>12</b> by, for example, a first tube support <b>134</b> and a second tube support <b>136</b>. The tube <b>132</b> may be supported at an angle with respect to the support surface <b>12</b> to cause the balls <b>130</b> to roll out of a lower end <b>140</b> of the tube <b>132</b> and onto the first tube support <b>134</b>. The first tube support <b>134</b> has a stop <b>138</b> to prevent the balls from rolling onto the support surface <b>12</b>. The cover-removal manipulator <b>30</b> may be used to transfer the balls <b>130</b> from the first tube support <b>134</b> to selected planting chambers.

Completing the description of the embodiment shown in FIGS. 1 and 2, the apparatus further includes a cleaning station <b>104</b> that comprises a housing having a pair of ports <b>106</b>, <b>108</b> for receiving the ends of respective probes <b>24</b>, <b>26</b> therein. The ports <b>106</b>, <b>108</b> are connected to a compressed-gas source for selectively applying compressed gas (e.g., compressed air) to the respective probes <b>24</b>, <b>26</b> for purposes of removing any seed debris remaining on the probes between successive seed-planting operations. Alternatively, the probes <b>24</b>, <b>26</b> may be subjected to a stream of compressed gas outside of any housing, although this may be less desirable in that any seed debris removed from the probes will not be contained for disposal. In another embodiment, the ports <b>106</b>, <b>108</b> are filled with a cleaning solution. In the latter configuration, additional ports may be provided for drying the probes <b>24</b>, <b>26</b> by, for example, applying compressed gas to the probes or flowing a hot gas over the probes.

In one approach for planting seeds with the apparatus <b>10</b>, the first probe <b>24</b> is used for removing the entire seed population from a donor jar and depositing the seeds in the alignment trough <b>110</b>, wherein the seeds become dispersed along the bottom <b>118</b> of the alignment trough <b>110</b>. When releasing the seed population into the alignment trough <b>110</b>, it is desirable to apply a low-pressure gas to the first probe <b>24</b>, as this ensures that all seeds are released from the probe and adequately dispersed along the bottom of the alignment trough <b>110</b>.

To remove individual seeds from the alignment trough <b>110</b> for planting in selected planting chambers, the end surface <b>92</b> of the second probe <b>26</b> is lowered to a position just above one end of the bottom <b>118</b> of the alignment trough <b>110</b> (FIG. <b>2</b>). The second probe <b>26</b> is then moved longitudinally of the trough <b>110</b> (e.g., in the x-direction in FIGS. 2 and 5) until the vacuum sensor <b>96</b> indicates that a first seed has been picked up by the second probe <b>26</b>. The second probe <b>26</b> is then raised out of the alignment trough <b>110</b> and moved to a position just above a selected planting chamber <b>18</b>, at which point the vacuum on the second probe <b>26</b> is removed to release the seed into the planting chamber. Low-pressure air may be applied to the second probe <b>26</b> to facilitate release of the seed.

After the first seed is planted, the second probe <b>26</b> can be moved back to the trough <b>110</b> to repeat the seed-planting operation for another seed in the alignment trough. This process can be repeated until all of the seeds in the alignment trough <b>110</b> have been planted in respective planting chambers <b>18</b>. Thereafter, the seed population of another donor jar <b>14</b> can be deposited into the alignment trough <b>110</b> with the first probe <b>24</b> and the seed-planting operation can be carried out for each seed in the alignment trough. This procedure can be repeated for each donor jar <b>14</b> until all of the planting chambers <b>18</b> have received at least one seed.

In some cases, it may be desirable to limit the number of seeds from each seed population (i.e., the seeds in a donor jar <b>14</b>) that are planted in respective planting chambers <b>18</b>. In one approach, for example, the number of seeds from each seed population that are planted is equal to a multiple of the number of planting chambers <b>18</b> in each row of planting chambers in a planting tray <b>16</b>. This prevents seeds from different seed populations from being planted in the same row of a planting tray <b>16</b>. When using planting trays <b>16</b> each having a 6×12 array of planting chambers <b>18</b>, for example, the number of seeds to be planted from each seed population may be limited to a maximum of eighteen seeds from each seed population so that no more than three rows of planting chambers <b>18</b> (6 planting chambers per row) will receive seeds from a seed population.

If a seed population has more than the maximum number of seeds to be planted (e.g., more than 18), the additional seeds may be removed and deposited back into the donor container <b>14</b> from which the seeds were originally removed. This may be accomplished by “sweeping” the first probe <b>24</b> along the bottom <b>118</b> of the trough <b>110</b> until all of the seeds have been picked up by the first probe <b>24</b>. The first probe <b>24</b> can then be moved back to the associated donor container <b>14</b> for depositing the seeds therein.

On the other hand, if a seed population has less than the maximum number of seeds which may be planted (e.g., less than 18 seeds), then an indicating element (e.g., a ball <b>130</b>) may be positioned in the seed-less planting chambers to facilitate identification of those planting chambers.

More specifically, FIGS. 9A-9D are a flow diagram illustrating in detail a program (either software or hard-wired program) according to one specific embodiment for carrying out a seed-planting process using the apparatus <b>10</b>. The illustrated program is configured to allow for the planting of seeds in planting trays having either a 6×12 array of planting chambers (such as shown in FIG. 5) or a 13×22 array of planting chambers. In either case, two planting trays of the same configuration will be provided for receiving seeds. In other embodiments, however, the number of planting trays and/or the number of planting chambers per tray can be varied.

In addition, the program allows for a maximum of 8 donor jars whenever 72-chamber planting trays (i.e., each tray having a 6×12 array of chambers) are selected and a maximum of 10 donor jars whenever 286-chamber planting trays (i.e., each tray having a 13×22 array of chambers) are selected. A seed population of approximately 18 seeds can be provided in each donor container <b>14</b> when using the 6×12 planting trays <b>16</b><i>a</i>, <b>16</b><i>b </i>shown in the illustrated embodiment. Alternatively, a seed population of approximately 52 seeds car be provided in each donor container <b>14</b> for use with the 13×22 planting trays. Of course, the number of donor jars <b>14</b> and/or the number the seeds per donor jar to be planted can be varied depending upon the particular application.

In the flow diagram, the following variables are specified by the operator and/or tracked by the program:

1. “Y” is the number of planting chambers (or cells) <b>18</b> in each planting tray <b>16</b>;

2. “N” is the number of available donor jars (or tubes) <b>14</b> from which seeds will be taken;

3. “J” is a counter that represents the number of the current donor jar <b>14</b> from which seeds are being taken;

4. “K” is a counter that represents the number of the current planting tray <b>16</b> into which seeds are being planted;

5. “L” is a counter that represents the number of the current planting chamber <b>18</b> (or cell);

6. “M” is a counter for the quantity of seeds from each donor tube J that have been planted; and

7. “X” is a counter representing the movement of the second probe <b>26</b> along the bottom of the alignment trough <b>110</b>.

Referring to FIG. 9A, the program starts at block <b>200</b> and then proceeds to input block <b>202</b>, at which point the user selects either the 72-chamber trays or the 286-chamber trays for use in the planting process. The program confirms at blocks <b>204</b>, <b>206</b>, and <b>208</b> that a proper selection has been made. At input block <b>210</b>, the user enters the number of donor tubes (jars) from which seeds will be taken. The program confirms at blocks <b>212</b> and <b>214</b> that no more than 8 donor tubes have been entered for use with the 72-chamber trays, and confirming at blocks <b>216</b> and <b>218</b> that no more than 10 donor tubes have been entered for use with the 286-chamber trays.

The program initializes variables J, K, and L to one, as indicated generally at <b>220</b>, and variable M to one at block <b>222</b>, then proceeds to the first seed-retrieval step, using a seed-retrieval subroutine indicated at process block <b>224</b>, which will be detailed below with reference to FIG. <b>9</b>E. The first seed-retrieval step operates to remove all of the seeds from the first donor jar (J=1) with the first probe <b>24</b> and to deposit the seeds in the alignment trough <b>110</b>.

After the seed-retrieval step, as shown in FIG. 9B, the program initializes the value of X to zero (block <b>226</b>), after which the vacuum to the second probe <b>26</b> is activated and the second probe <b>26</b> is moved into position directly above one end of the bottom <b>118</b> of the alignment trough <b>110</b> (as indicated generally at <b>228</b>). The control unit <b>42</b> reads the output of the vacuum sensor <b>96</b> at blocks <b>230</b> and <b>232</b>, and confirms at block <b>234</b> that the vacuum applied to the second probe <b>26</b> is stable to within an acceptable degree.

If the vacuum to the second probe <b>26</b> is sufficiently stable, then the second probe <b>26</b> is lowered to a position just above one end of the bottom <b>118</b> of the alignment trough <b>110</b> (block <b>236</b>), after which the control unit <b>42</b> again reads the output of the vacuum sensor <b>96</b> (block <b>238</b>). The program then determines at decision block <b>240</b> whether the change in the level of vacuum in the second probe <b>26</b> is greater than a predetermined value.

If the change in vacuum exceeds the predetermined value, indicating that the second probe <b>26</b> has picked up a seed, the programs proceeds to the first seed-planting step, using a seed-planting subroutine indicated at process block <b>248</b>, which will be detailed below with reference to FIG. <b>9</b>F. The first seed-planting step operates to raise the second probe <b>26</b> out of the alignment trough <b>110</b>, move the second probe <b>26</b> to a position above the first planting cell (L=1), and deposit the seed into the first planting cell.

If, on the other hand, the change in vacuum does not exceed the predetermined value (as determined at decision block <b>240</b>), indicating that the second probe <b>26</b> has not picked up a seed, the program proceeds to increment the value of X at block <b>242</b>. The program then executes an algorithm at decision block <b>244</b> to determine the position of the second probe <b>26</b> relative to the far, or opposite, end of the bottom <b>118</b> of the alignment trough <b>110</b> (i.e., the end opposite the end at which the second probe <b>26</b> is positioned at block <b>236</b>). If it is determined that the second probe <b>26</b> is not at the far end of the alignment trough <b>110</b>, the second probe <b>26</b> is moved a predetermined distance (e.g., 5 mm) toward the opposite end, as indicated at block <b>246</b>. The program then loops back to blocks <b>238</b> and <b>240</b> to read the output of the vacuum sensor and to determine whether the second probe <b>26</b> has picked up a seed, respectively. The program repeats itself in accordance with the process loop defined by blocks <b>238</b>, <b>240</b>, <b>242</b>, <b>244</b>, and <b>246</b> to move the second probe <b>26</b> along the bottom of the trough until a seed is picked up (block <b>240</b>) or the second probe reaches the far end of the alignment trough <b>110</b> without picking up a seed (block <b>244</b>).

As mentioned, whenever the second probe <b>26</b> picks up a seed in the alignment trough <b>110</b>, the seed-planting subroutine is carried out for the seed (block <b>248</b>) and the value of L (the planting-chamber number) is incremented at block <b>250</b>. If the 72-chamber trays are being used (as determined at block <b>252</b>), then the program proceeds to block <b>254</b> to determine whether the maximum number of seeds from the current donor population (e.g., 18 in this case) have been planted. On the other hand, if the 286-chamber trays are being used (as determined at block <b>256</b>), then the program proceeds to block <b>258</b> to determine whether the maximum number of seeds from the current donor population (e.g., 52 in this case) have been planted. If the answer is “no” for either the 72-chamber or 286-chamber trays, the program increments the value of M (block <b>260</b>) and loops back to a point in the program immediately following block <b>226</b> for retrieving another seed from the alignment trough <b>110</b>. This process is repeated until a predetermined number of seeds in the alignment trough <b>110</b> (up to 18 or 52 seeds) have been planted in corresponding planting cells <b>18</b>, at which point the program proceeds to the first seed-removal step, using a seed-removal subroutine indicated at process block <b>262</b> (FIG. <b>9</b>C). The seed-removal subroutine is described in greater detail below with reference to FIG. <b>9</b>H. The first seed-removal step operates to sweep the first probe <b>24</b> along the bottom <b>118</b> of the alignment trough <b>110</b> for picking up any additional seeds, move the first probe <b>24</b> to a position above the first donor jar (J=1), and deposit the additional seeds back into the first donor jar.

After the seed-removal step is complete, the probes <b>24</b>, <b>26</b> may be cleaned in the cleaning station <b>104</b> to remove any debris from the probes, as indicated at <b>264</b>. Although not shown, the compressed air to the air knife <b>116</b> may be activated to clear out any debris in the alignment trough <b>110</b>. As shown, the value of K (the planting-tray number) is increased to 2 to begin planting seeds in the second planting tray <b>16</b> when the value of L (the planting-chamber number) exceeds a predetermined value (72 chambers for a 72-chamber tray, as indicated at blocks <b>266</b> and <b>268</b>, or <b>260</b> chambers for a 286-chamber tray, as indicated at blocks <b>270</b> and <b>272</b>). The value of J (the donor-jar number) is incremented at block <b>274</b>, after which the program loops back to a point just prior to block <b>222</b> (FIG. 9A) to execute a seed-retrieval step for the second donor jar (J=2) using the seed-retrieval subroutine at block <b>224</b>. As mentioned, the seed-retrieval step operates to remove the seed population from the current donor jar <b>14</b> and deposit the seed population in the alignment trough <b>110</b>. After the seed-retrieval step is completed, a predetermined number of seeds are planted in corresponding planting cells (FIG. <b>9</b>B) and any additional seeds are transferred back to the current donor jar (block <b>262</b>, FIG. <b>9</b>C). This process is repeated for each donor jar (up to 8 jars when using the 72-chamber trays and up to 10 jars when using the 286-chamber trays), that is until J&gt;N, as indicated at block <b>276</b>.

As described above, a process loop defined by blocks <b>238</b>, <b>240</b>, <b>242</b>, <b>244</b>, and <b>246</b> of FIG. 9B operates to move the second probe <b>26</b> along the bottom of the alignment trough <b>110</b> until a seed is picked up (block <b>240</b>) or the second probe reaches the opposite end of the alignment trough <b>110</b> without picking up a seed (block <b>244</b>). The latter scenario can occur if a seed population had less than the allowable number of seeds to be planted (e.g., less than 18 if the 72-chamber trays are being used or less than 52 if the 286-chamber trays are being used).

A subroutine may be executed to confirm that there are no seeds remaining in the alignment trough <b>110</b>. This may include optionally cleaning the second probe <b>26</b> at the cleaning station <b>104</b> (block <b>280</b>), setting the value of X, for example, to 225 (block <b>282</b>), and lowering the second probe <b>26</b> back into the alignment trough <b>110</b> (block <b>284</b> of FIG. <b>9</b>D). By setting the value of X to 225, the second probe <b>26</b> is positioned intermediate the ends of the alignment trough, about {fraction (6/7)} of the distance to the far end of the trough. Of course, the value assigned to X at block <b>282</b> can vary. In any event, a process loop defined by blocks <b>286</b>, <b>288</b>, <b>290</b>, <b>292</b>, and <b>294</b> operates to move the second probe <b>26</b> toward the far end of the alignment trough <b>110</b> until a seed is picked up (block <b>288</b>) or the second probe reaches the opposite end of the alignment trough <b>110</b> without picking up a seed (block <b>292</b>).

If the second probe <b>26</b> picks up a seed, the seed-planting subroutine is executed for the seed (block <b>296</b>) and the program loops back to block <b>284</b>, repeating the process until the maximum allowable number of seeds have been planted in corresponding planting cells <b>18</b>. The program then continues at block <b>262</b> of FIG. <b>9</b>C. If, however, the second probe <b>26</b> reaches the far end of the alignment trough <b>110</b> without picking up a seed, thereby confirming that there are no seeds remaining in the alignment trough <b>110</b> (and that the donor population had less than the allowable number of seeds to be planted), then the program proceeds to the ball-transfer subroutine at block <b>298</b>.

The ball-transfer subroutine, which is described in greater detail below in connection with FIG. 9G, operates to pick up a ball <b>130</b> with the cover-removal manipulator <b>30</b> and place the ball in the current planting cell (L) to indicate that a seed has not been planted in that planting cell. After the ball <b>130</b> has been placed in a corresponding planting cell <b>18</b>, the values of L and M are incremented, as indicated at blocks <b>300</b> and <b>302</b>, respectively, until M&gt;17 if the 72-chamber trays are being used, as indicated at block <b>304</b>, or until M&gt;51 if the 286-chamber trays are being used, as indicated at block <b>306</b>. When one of the latter two conditions is satisfied, the value of L (the planting-chamber number) will be equal to the identification number of a planting chamber <b>18</b> at the beginning of a row of planting chambers (e.g., L=19, 37, 55, etc. if the 72-chamber trays are being used or L=53, 105, 157, etc., if the 286-chamber trays are being used). Accordingly, the first seed of the succeeding donor population removed from the alignment trough <b>110</b> will be planted in a planting chamber <b>18</b> at the beginning of a row of planting chambers.

In the method illustrated in FIG. 9D, a ball <b>130</b> is placed in the first planting chamber <b>18</b> for which a seed is not available, but not in any other planting chambers in the same row for which seeds are not available. It should be recognized that the use of a single ball <b>130</b> is sufficient to indicate that the respective planting chamber <b>18</b> that contains the ball, and any other planting chambers of a higher number in the same row, do not contain a seed. This is because the first seed of the next donor population will be planted in the first planting chamber <b>18</b> of the next row. However, if desired, a ball <b>130</b> may be placed in each planting chamber <b>18</b> that does not contain a seed. In addition, in other embodiments, the program may proceed directly from block <b>244</b> of FIG. 9B to the ball-transfer subroutine at block <b>298</b> of FIG. 9D, without first executing the subroutine described above for confirming whether there are any seeds remaining in the alignment trough <b>110</b>.

In any event, as shown in FIG. 9D, the program increments the value of J (the donor-jar number) at block <b>308</b>. If the condition at block <b>304</b> is not satisfied (indicating that there are remaining donor jars <b>14</b>), then program loops back to a point just prior to block <b>222</b> (FIG. 9A) to execute another seed-retrieval step for the next donor jar.

The seed-planting method given in FIGS. 9A-9D involves (i) steps for transferring a seed population from a selected donor jar <b>14</b> to the alignment trough <b>110</b>, shown generally at <b>400</b> in FIG. 9E, (ii) steps for transferring individual seeds from the alignment trough <b>110</b> to selected planting cells <b>18</b>, shown generally at <b>500</b> in FIG. 9F, (iii) steps for transferring an indicating ball <b>130</b> from the tube support <b>134</b> to selected planting cells <b>18</b>, shown generally at <b>600</b> in FIG. 9G, (iv) steps for transferring seeds from the alignment trough <b>110</b> to a selected donor jar <b>14</b>, shown generally at <b>700</b> in FIG. 9H, and (v) steps for cleaning the first and second probes <b>24</b>, <b>26</b>, respectively, at the cleaning station <b>104</b>, as shown generally at <b>800</b> in FIG. <b>9</b>I.

With specific reference to FIG. 9E, if the user specifies that the donor jars <b>14</b> have covers, then the cover-removal manipulator <b>30</b> is operated to remove the cover of the current donor jar <b>14</b>, as indicated generally at <b>400</b><i>a</i>. As described, initial movement of the head assembly <b>28</b> to remove a cover results in placement of the jaws <b>66</b> of the manipulator <b>30</b> directly above the current jar, at which point the cover-removal manipulator <b>30</b> is moved downward in the z direction to a position to engage the cover. After the manipulator <b>30</b> has been activated to engage the cover and remove the cover from the selected jar <b>14</b>, and with the cover held in the clamping jaws <b>66</b>, the cover-removed manipulator <b>30</b> is raised in the z direction.

The head assembly <b>28</b> is then shifted in its x-y position to place the appropriate seed pick-up probe directly above the now-opened jar, as indicated generally at <b>400</b><i>b</i>. Of course, if the donor jars <b>14</b> do not have covers, then the program skips the steps at <b>400</b><i>a </i>and proceeds directly to the first step at <b>400</b><i>b</i>. In either case, the probe referred to at <b>400</b><i>b </i>desirably is the first probe <b>24</b> (FIGS. <b>6</b>A and <b>6</b>B), which, as previously explained, is designed to pick up most, if not all, of the seed population in a donor jar. To pick up the seeds in the donor jar <b>14</b>, the first probe <b>24</b> is lowered in the donor jar, and the vacuum supply to the device is activated so that seeds are drawn to and held by the negative pressure at the openings of the end surface <b>86</b> of the probe <b>24</b>.

After seed pick-up from the opened donor jar <b>14</b>, the head assembly <b>28</b> is shifted again to place the cover-removal manipulator <b>30</b> directly above the jar. The cover-removal manipulator is activated to screw the cover back on the jar and then release the cover from the jaws <b>66</b>, as indicated at <b>400</b><i>c</i>. To deposit the seeds into the alignment trough <b>110</b>, the head assembly <b>28</b> is shifted to place the first probe <b>24</b> at a position above the alignment trough <b>110</b>, as indicated at <b>400</b><i>d</i>. The first probe <b>24</b> is lowered into the alignment trough <b>110</b> and the vacuum supply to the probe is released to cause the seeds to fall into the alignment trough. The low-pressure air supply to the first probe <b>24</b> may be activated to ensure that all seeds are released from the probe.

FIG. 9F shows a flow chart for the seed-planting subroutine according to one embodiment, indicated generally at <b>500</b>. Whenever the second probe <b>26</b> picks up a seed in the alignment trough <b>110</b> (e.g., at block <b>240</b> of FIG. 9B or block <b>288</b> of FIG. <b>9</b>D), the second probe is raised out of the alignment trough in the z-direction and the head assembly <b>28</b> is shifted to place the second probe directly over the current planting cell <b>18</b>. The second probe <b>24</b> is lowered into the planting cell and the vacuum supply to the probe is released to cause the seed to fall into the planting cell. The low-pressure air supply to the second probe may be activated to ensure that the seed is released from the probe.

Referring to FIG. 9G, a ball-transfer sub-routine according to one embodiment involves raising the second probe <b>26</b> out of the alignment trough <b>110</b> and shifting the x-y position of the head assembly <b>28</b> so that the jaws <b>66</b> of the cover-removal manipulator <b>30</b> are situated directly above a ball <b>130</b> supported on the first tube support <b>134</b>. The cover-removal manipulator <b>30</b> is lowered to a position to engage the ball. After the ball has been grasped by the jaws <b>66</b> of the cover-removal manipulator, the cover-removal manipulator is raised. The head assembly <b>28</b> is shifted to place the cover-removal manipulator <b>30</b> directly above the current planting cell <b>18</b>. The manipulator is then lowered and the jaws <b>66</b> are activated to release the ball <b>130</b> into the planting cell <b>18</b>.

Referring to FIG. 9H, a seed-removal subroutine according to one embodiment involves shifting the x-y position of the head assembly <b>28</b> so that the first probe <b>24</b> is positioned directly above one end of the alignment trough <b>110</b>, as indicated at <b>700</b><i>a</i>. The vacuum supply to the first probe <b>24</b> is activated and the first probe <b>24</b> is lowered into the alignment trough and then moved to the opposite end of the alignment trough, thereby picking up any seed(s) that lie along the bottom <b>118</b> of the trough. The head assembly <b>28</b> is shifted again to position the cover-removal manipulator <b>30</b> above the current donor jar <b>14</b>. The cover-removal manipulator <b>30</b> is activated to remove the cover from the donor jar <b>14</b>, as indicated at <b>700</b><i>b</i>. After the cover is removed from the donor jar, the head assembly <b>28</b> is shifted to place the first probe <b>24</b> into position above the donor jar, as indicated at <b>700</b><i>c</i>. The first probe <b>24</b> is lowered into the donor jar and the vacuum supply to the probe is released to cause the seed(s) to fall into the donor jar. The low-pressure air supply to the first probe <b>24</b> may be activated to ensure that all seeds are released from the probe. Finally, as indicated at <b>700</b><i>d</i>, the cover-removal manipulator <b>30</b> is operated to replace the cover on the donor jar.

FIG. 9I shows a flow chart for carrying out the probe-cleaning step. This step may involve cleaning either one probe only or both probes <b>24</b>, <b>26</b> simultaneously. In this subroutine, the x-y position of the head assembly <b>28</b> is shifted to position the probes <b>24</b>, <b>26</b> above respective ports <b>106</b>, <b>108</b> in the cleaning station <b>104</b>. One or both probes are lowered into the cleaning station <b>104</b> and cleaned, such as by “submersion” in a compressed air bath and/or by directing high-pressure air through the probes, to prevent any possibility of seed carryover. Cleaning of both probes <b>24</b>, <b>26</b> is desirable after completing a seed-removal subroutine (as indicated at block <b>264</b> in FIG. 9C) and after completing of a ball-transfer routine (as indicated at block <b>299</b> in FIG. <b>9</b>D). Alternatively, if desired, the program may exclude the probe-cleaning steps.

In an alternative method for planting seeds with the apparatus <b>10</b> of FIGS. 1 and 2, seeds may be removed from their respective donor containers <b>14</b> and deposited in selected planting chambers <b>18</b> with the second probe <b>26</b>. In this case, the seed-alignment trough <b>110</b> and the first probe <b>24</b> can be optional.

The invention has been described with respect to particular embodiments and modes of action for illustrative purposes only. The present invention may be subject to many modifications and changes without departing from the spirit or essential characteristics thereof. We therefore claim as our invention all such modifications as come within the scope of the following claims.